The World Wide Web has become a popular reference tool to search for information due to its large collection of documents. However, finding information in such a large document collection can often be a challenging and time-consuming task. For example, a user must decide which search engine to use and how to best phrase his/her search request. To verify the results, some users may even repeat the search using slightly different words or changing the order of the words. More and more, looking for the desired information can be rather cumbersome. In addition, the abilities of search engine users can vary immensely. For instance, information that might take one user a few seconds to find may take several minutes or be impossible for another user to find.
Coincident with some of these concerns, numerous systems have been built for community question answering. Examples of these conventional systems include Usenet newsgroups where a user posts a question to a particular topic group and persons or people who monitor that group individually respond to the question. Google Answers is similar except that user offers to pay money to have their questions answered. Naver, a Korean search engine, even offers points for those who individually answer a question posted by another user. The systems currently in operation do provide answers for users, however, the integrity or accuracy of the answer may not or cannot be checked or known, and often the user is still left with the task of determining the right answer. Another problem with these systems is that the throughput is limited because a relatively small number of people participate in providing answers.